spray bars for Ford Uprated Kent's & Cortina's
there's nothing tricky required to make spray bars for your Uprated Kent/Cortina. unlike most of the Cup spray bars I've seen that tend to be one piece 1/4" OD aluminum tubing, three pieces of 3/16" OD x 0.020" wall stainless tubing were used for the valve cover spray bars shown in the first picture. lack of space for spray bars on the inside of Uprated Kent/Cortina valve covers is the biggest challenge. the spray bar installation in the first picture did not yield sufficient clearance so had to be redone. the valve cover attachment/hold down fastener locations all but dictates a three piece solution. the 3/16" OD stainless tubing saves space; the 0.020" wall leaves more than adequate flow area, and naturally taps 8-32 UNC. it hurts my head to even think about the need to mill, drill, or ream the ID of thin wall stainless tubing to enable tapping....... lack of space on the inside of the valve cover dictates that all connections be done on the outside and that the fittings be located adjacent to rocker shaft support stands. the lack of space is highlighted in the second picture showing the milling and back spot facing required to clear the valve springs even with the 3/16" OD tubing!
fabricating the actual spray bars is all detail work. the spray bars started life as AN-3 bulkhead unions (AN832) as shown in the third picture. the thickness of the hex was reduced to 3/16" and the short side fitting removed. then a 3/16" OD hole was milled through one of the hex faces and the now flat face bored 3/32" deep. stainless tubing cut to length and tapped on both ends was then centered in the fittings and the assemblies silver soldered (remember to order flux). getting everything clean after soldering is a pain that a little vinegar and an old coffee cup will fix in a day or two. when things are clean, the supply hole and the spray holes will need to be milled and deburred on the inside before the socket-head set screws can be silver soldered in the ends.
things on the outside and final installation are straight forward: an approximation of an o-ring boss port in the valve cover, a viton o-ring, a stainless flat washer to protect the o-ring during assembly, and a MS half-height nut with a nylon locking insert; see picture four. remember to include the compressed thickness of your valve cover gasket in picking the height to drill holes in the valve cover. XRP aluminum swivel fitting enable things to be done with two straight tube assemblies; I used thinwall stainless for flow area. straight hard lines between two fixed points should as a rule be avoided but lack of space (heat shield, headers, EGT's, plug wires) dictated that solution here. when forced into this corner I prefer tube assemblies under very slight compression requiring things to be turned into place. if your tube assembly is too long it can be shortened slightly and re-flared; going slowly pays dividends in the end. if in spite of going slowly you find yourself with a tube assembly that's too short, an aluminum conical seal on one or both ends might be enough to avoid starting over.......
space for the camshaft spray bar isn't nearly as difficult but access is far worse than for the valve cover. I'm using AN-4 fittings and 1/4" stainless tubing for the camshaft spray bar principally for higher flow. two spray holes per lobe are being used to eliminate a potential internal (ie: out of sight) single point failure mechanism. a support clamp per camshaft spray bar is recommended to assure providing oil to the intended spot (aim) and preventing tuning fork like motion (fatigue failure) of the spray bar.
Art
artesmith@earthlink.net
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